Toilets assemblies on almost all modern boats and on recreational vehicles (RV) have to pump toilet waste into a holding tank which retains the waste until the waste can be safely emptied into an approved environmentally compliant waste facility. The conventional plumbing requires pumping the waste out and upward by a sanitation hose, which typically has a 1.5 inch inside diameter, upward about three to five feet, over a top loop, then the waste is allowed to flow downward into the holding tank where the waste is stored.
The upward loop is above the sea water line outside the vessel (boat) which isolates the inward flow of the sea in the event of a plumping failure. The upward loop also allows the waste to be isolated from the interior of the boat or RV in the event of toilet mechanism or hose failure. When on the open sea or ocean, waste discharge is permitted, but the waste must still be pumped up and over this upward loop, then down into the open sea or ocean.
Because there is always a 1.5 inch inside diameter sanitation hose flowing uphill against gravity three to five feet, this waste tends to backflow into the toilet bowel. To prevent this backflow, a check valve is installed at the toilet.
Prior art check valves for preventing such a backflow are made of made of elastomer rubber, typically neoprene. There are typically two styles, namely, a single valve sometimes called a “duck bill”, and a tri-valve Y with three separate lobes. These prior art check valves seal based upon manufactured molded in stress. The prior art check valves tend to stretched out in use, and then lose elasticity. As a result, liquid waste leaks back into the toilet, which highly undesirable on a RV or on a boat.
Saltwater and seas contaminates can also interfere with the natural sealing of a check valve.
A check valve for use in toilet assembly of a RV or a boat is provided herein which provides improvements to the existing prior art and which overcomes the disadvantages presented by the prior art. Other features and advantages will become apparent upon a reading of the attached specification, in combination with a study of the drawings.